Incandescent lamp and similar article



R; F. STRICKLAND INGANDES-CENT LAMP AND SIMILAR ARTICLE I Filed May 13. I919 JNVE'ATTM?! fia u. FETEJEKLAM? Fig. 4

fi's Arraawzr Patented Apr. 22, 1924.

h STTES ROYAL F. STRICKLAND, F CLEVELAND,

OHIO, ASSIGNOR TO GENERAL. ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

INCANDESCENT LAMP AND SIMILAR ARTICLE.

Application filed. may 13,

T 0 (ZZZ whom it may concern:

Be it known that I, ROYAL F. STRICKLAND, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga, State of Ohio, have invented certain new and useful Improvements in Incandescent Lamps and Similar Articles, of which the following is a specification.

My invention relates to tipless incandescent lamps and similar articles, and more particularly to tipless miniature lamps. In this application the expression similar articles is used to indicate other articles comprising bulbs into which one or more wires are sealed.

Heretofore tipless miniature incandescent lamps have commonly been made by a method known as butt-sealing. In this method, a miniature mount is placed inside the bulb, which has a short neck but is otherwise smooth, and an exhaust tube of substantially the same size as the neck is fused to the neck, the leading-in wires passing to the outside at the line of fusion. A contraction is formed in the exhaust tube adjacent to the line of fusion. After the exhausting operation is completed, the exhaust tube is fused off at the contraction to form a closure. This method has the disadvantage that the leading-in wires'are sealed in thin glass and are easily cracked out and thus cause air leaks if subjected to much handling before being based.

In the method of my invention, the leading-in wires are sealed into a clamped portion of the neck part of the lamp through which an opening is formed and to which is fused an exhaust tube. To form the opening through the seal, I use a refractory body, preferably a metal, although carbon or other refractory non-metal may be used to advantage. It has been attempted heretofore to us a refractory body to maintain a passage through fused glass but in these attempts the refractory body was permitted to become heated and consequently was wet-ted by the glass. When the refractory body was withdrawn, the lass adhered to it and the passage was distorted or destroyed. According to my invention, the refractory body is prevented from becoming heated and the glass does not wet or adhere to the said body and the latter may be withdrawn leaving an unrestricted passage through the seal into the bulb. The

1919. Serial No. 296,741.

leading-in wires are firmly sealed in a body of comparatively thick glass and the lamp is less subject to air leaks because of faulty seals than in the case of butt-seals. The lamp is exhausted, the exhaust tube fused off to form a closure. and the lamp based by the well-known methods. It may be noted incidentally that a very effective closure may be formed immediately below the clamped portion without necessitating the formation of a special contraction in the exhaust tube as in present practice.

My invention also comprises an improved incandescent lamp or similar article and an apparatus for the carrying out of my improved method, specific embodiments of said article and apparatus being described in this specification and the scope ,of the invention being set forth in the appended claims.

In the drawing, Fig. 1 is a front elevation of a miniature lamp sealing-in machine comprised by my invention; Fig. 2 is a side elevation of the same; Fig. 3 is a front elevation showing the clamping members in the closed position; Fig. 4 is a top plan View of the machine of Fig. 1; Fig. 5 is an enlarged fragmentary sectional elevation of the clamping jaws and associated parts closed upon the neck part of a miniature lamp; Fig. 6 is a front elevation of a miniature lamp at one stage in its manufacture according to my invention; Fig. 7 is a side elevation, partially in section, of the lamp of Fig. 6; and Fig. 8 is a. front elevation partially in section of a completed miniature lamp made by my method.

Referring tov the drawing, the table 1 car-- ries a bearing standard 2 and bearing 3 upon which rotates a pulley 4. Through the center of the pulley 4, standard 2, and table 1, passes a tubular support 5 having a head 6 with a slightly concave top for the reception of a miniature lamp bulb 7. The lower end of the tubular support 5 is connected by a link 8, rotatably attached to the support 5 by means such as the screw 9 which serves as a bottom closure to the tube 5, to the rack 10 passing through the table 1 and slidably attached to the standard 2. The rack 10 is engaged by a pinion 11 fastened to a shaft 12 carrying the handwheel 13 by rotation of which the tubular support 5 may be raised or lowered. The standard 2 contains a chamber 14 connected to a source of air suction through the pipe '15 and communicating with the tubular support 5 through the opening 16. The air suction serves to hold the bulb 7 upon the head 6 while the operation of sealing is performed.

Thepulley 4 carries near its outer edge a square upright support 17. Attached near the middle of the upright 17 is a horizontal arm 18 split to receive an exhaust tube 19 and to hold it in the vertical axis of the pullcy 4 by means of the pressure exerted on the split portion by the spring 20 carried on the bolt 21 passing through the split portion. Above the arm 18 is fastened a stop 22 upon which rests a spring 23 which supports a cap 24 slidable on the upper end of upright 17. The cap 24 is connected through two similar links 25 and 26' to the two clamping members 2'? and 28 which are attached to a block 29 fastened to the upright 17. The cap 24 also carries a horizontal arm 30: with an opening in the end in alignment with the vertical axis of the pulley 4 through which passes a rod 31 of refractory material carrying a stop 32 resting upon a spring 33 carried by the horizontal arn; 30. For the refractory material of the rod 31, tungsten is preferred although other metals or non-metallic refractory materials may be used.

Downward pressure applied to the top of the cap 24, acting through the links 25 and 26, causes the clamping members 27 and 28 to close. Complete closure of the clamps is obviously not desired and the amount of closure is regulated by adjusting the screw 34, in the top of the cap 24, which butts against the top of the upright support 17 and so arrests the downward movement of the cap 24 with the clamps 27 and 28 in the desired relative positions. The refractory rod 31 moves with the cap 24 in its downward movement and is of sufficient length to pass a slight distance beyond the jaws of the clamping members when the latter are in the desired relative positions, as shown in Figs. 3 and 5. The jaws of the clamping members each have a notch 35 which aligns with the rod 31 and permits a space to exist between the rod and either jaw when the clamping members are in the closed position shown in Figs. 3 and 5.

To assemble, a lamp bulb 7 is placed on the support head 6, being held in place by air suction, and a mount 36 is placed therein, as shown in Fig. 2, being held in proper relation by bends in the leading-in wires 37. Through the handwheel 13, the head 6 is ad justed until brought into position where the jaws of the clamping members will close upon the neck part of the bulb 7 when downward pressure is applied to the top of the cap 24. One adjustment of this nature is preferable for each size of bulb. The rod 31 is inserted in an exhaust tube 19 which is then placed in the end of the horizontal arm 18 with the lower end of the tube 19 substantially on a level with the end of the neck part of the bulb 7,

In operation, the parts are thus assembled and the pulley 4 rotated, the support 5 retating therewith, while gas flames (not shown) fuse the neck part of the bulb and the lower end of the exhaifst tube: When the glass has sufiiciently softened, the gas flames are shut off, rotation stopped and downward pressure is applied to the top of the cap'24. bers 27 and 28' close upon the fused glass of the neck part and exhaust tube to form the seal at the same instant that the .rod 31 has passed through the neck part and entered the bulb, as shown in Fig. 5. The glass is firmly pressed around the leadingin wires and the rod 31 which forms a passageway through the exhaust tube into the bulb, the exhaust tube uniting with the neck part of the bulb. The pressure is then rleased and the spring 23 returns the cap 24 which action opens the clamping members and tends to compress the spring 33 which thereupon exerts a pressure upward to withdraw the rod 31. The lamp with exhaust tube, as shown in Figs. 6 and 7, is then removed. The lamp is afterwards exhausted, sealed off and based according to the usual practice.

What I claim as new and desire to secure by Letters Patent of the United States,

1. The method of manufacturing incan= descent lamps and similar articles which comprise a bulb and leading-in wires, which consists in fusing the walls of the bulb neck to inclc-se the leading-in wires, then inserting a refractory body and clamping the fused glass around the same and finally withdrawing the said refractory body.

2. The method of manufacturing incandescent lamps and similar articles which comprise a bulb and leading-in wires, which consists in fusing the walls of the bulb neck to inclose the leading-in wires, then inserting a cool refractory body to form a passage through the body of glass thus formed and afterwards withdrawing said refractory body.

3. The method of manufacturing incandescent lamps and similar articles which comprise a bulb and leading-in wires, which consists in fusing the walls of the bulb neck to inclose the leading-in wires, inserting a cool refractory body to form a passa e through the body of glass thus formed, substantially simultaneously clamping the body of glass about the wire and the refractory body and finally withdrawing said refractory body.

4. The method of forming a passage The jaws of the clamping men1= through a glass part for electric incandescent lamps and other electrical devices comprising leading-1n wires, which consists memes in extending said wires through said part, fusing a portion of said part so that the wires are embedded therein, then inserting a refractory body to form a passage through the fused mass and finally withdrawing said refractory body.

5. The method of forming a passage through a glass part for electric incandescent lamps and other electrical devices comprising leading-in wires, which consists in extending said wires through said part, fusing a portion of said part so that the wires are embedded therein, then inserting 'a refractory body to form a passage through the fused mass between the leading-in wires and finally withdrawing said refractory body.

6. The method of forming a passage through a glass part for electric incandescent lamps and other electrical devices comprising leading-in wires, which consists in extending said wires through said part, fusing a portion of said part so that the wires are embedded therein, then inserting a refractory body to form a passage through the fused mass, clamping the fused glass around said leading-in wires and said refractory body andfinally withdrawing said refractory body.

7. The method of forming 'a passage through a glass part for electric incandescent lamps and other electrical devices comprising leading-in wires, whieh consists in extending said wiresv through said part, fusing a portion of said part sothat the wires are embedded therein, then inserting ing-in wires and said refractory body, and finally withdrawing said refractory body.

8. The method of manufacturing incandescent lamps and similar articles which comprise a bulb and leading-in wires, which consists in fusing the walls of the bulb neck to inclose the leading-in wires and to unite an exhaust tube to said bulb neck, then inserting a refractory body through said exhaust tube to form a passage through the fused body of glass to the bulb, then clamping the fused glass around the said refractory body and finally withdrawing the said refractory body.

9. The method of uniting an exhaust tube to a glass part for electric incandescent lamps and similar devices which consists in fusing a portion of said part around the end of said tube, then inserting a refractory body through said tube to form a passage through the body of glass formed by said fusion and afterwards withdrawing the said refractory body.

In witnesswhereof, I have hereunto set my hand this ninth day of May, 1919.

ROYAL F. STRICKLAND. 

